1. Field of the Invention
The present invention relates to a dyestuff, and more particularly relates to a fiber reactive dyestuff having low salt and low alkalinity suitable for dyeing and printing cellulose fiber or fiber materials containing cellulose.
2. Description of the Related Art
The fiber reactive dyestuffs are used widely in the dyeing industries for many years, and the primary characteristic is: the reactive groups of the dyestuff molecules may react with the groups on the fibers covalently. Numerous patents are disclosed, for example, in the U.S. Pat. Nos. 4,703,112; 5,484,899; 6,329,514 and British patent GB 1,353,899 there disclosed the commonly used fiber reactive dyestuffs having good build up and other fine dyeing properties suitable for exhaustion dyeing, continuous dyeing or printing.
However the present development of reactive dyestuffs is aiming for economic reactive dyestuffs having high fixation, high build up and wash-off, therefore the properties of the new generation reactive dyestuffs should not only having sufficient substantivity for increasing the chance of fixation, it is also important for the unfixed dyestuffs to have fine wash-off property.
The present inventors invested tremendous amount of research for reactive dyestuffs satisfying the present need, so that the aforementioned problem can be resolved. It is then realized that the aforementioned problem can be solved with the use of reactive azo dyestuff of quaternary ammonium salts. .The reactive groups of this kind of quaternary ammonium salts can temporarily enhancing the substantivity of the dyestuffs, and to the fibers demonstrating a higher affinity while having properties of wash-off, biodegradable, good build up, good light fastness, good wash fastness and good chlorine bleaching fastness; as well performs well in other fastness testing and at the same time having the properties of compatibility and fiber level dyeing.